A passport is a doorway to the world—at least for those who, based on the arbitrariness of place of birth, possess one deemed “powerful” enough to grant the freedom to travel it with relative ease. But the evolution of the passport hasn't been a straight path, and the document we recognize today is still fairly new. Although the earliest reference to a passport-like document dates to 450 B.C., and Henry V of England began granting travel documents to his subjects in the 15th century, it wasn't until the early 20th century that passport design was standardized and the palm-sized booklet really took shape. Here are some of the oddest passport facts.

Mummy mugshot

There's no known record of anything like a passport existing in ancient Egypt. But in 1974, when the mummy of Ramses II (died 1213 B.C.) had to be flown to Paris for restoration, it was issued a valid Egyptian passport, including a photo of the pharaoh's ancient face. His occupation was listed as “King (deceased).”

Royal rights

Had there been passports during Ramses’ six-decade rule, he likely wouldn’t have needed one, anyway: Living monarchs do not generally require passports. The U.K. Royal Family's official website explains that “as a British passport is issued in the name of Her Majesty, it is unnecessary for The Queen to possess one.” Indeed, a message inside a U.K. passport’s cover requests that the bearer be allowed to pass freely “in the Name of Her Majesty.” Basically, the Queen is a passport.

Similarly, in Japan, it was decided that it would be “inappropriate” to issue the Emperor a Japanese passport, which bears the imperial seal of the Chrysanthemum Throne on its cover and contains “a foreign minister’s request to allow the holder to travel without trouble.” Though when Emperor Akihito abdicates next spring, he will, like the rest of the Imperial family, need one for future international travels.

High flyers

While international borders are very much a human construct, an ancient mummy is not the oddest entity to have required a passport. The peregrine falcon's name may mean “wanderer” but in the United Arab Emirates, they can’t go wandering far without a passport. Falcons—specifically saker and peregrine falcons—are highly prized in the U.A.E., where falconry is a significant part of the region’s Bedouin heritage. Once essential for hunting, the sport continues to be a source of national pride.

Unfortunately with the falcon’s high status (and monetary value) comes the risk of smuggling, so falcons in the Emirates get their own green, U.A.E.-issued passports for jetting around the world to falconry festivals and competitions. Each passport has its own identification number corresponding to the number inscribed on the falcon’s leg ring and, just like those of humans, it must “be endorsed by the appropriate border control officer who should validate it with an ink stamp, signature and date to show the history of movement from State to State.”

Horsing around

Animal passports are more common than you might expect. While pets in the United States can get paperwork permitting them to cross borders with minimum hassle, European Union pets actually get their own blue booklets, complete with a photo inside the cover. E.U. Pet Passports allow quarantine-free travel between member countries, a scheme so beloved that, in October, hundreds of dogs (and their owners) took to the streets of London in a wooferendum, protesting the threat posed by Brexit to their prized passports.

British horses, on the other hand, require horse passports even if they never venture farther than their field—the policy is meant to ensure that horses treated with drugs harmful to humans do not get sent for slaughter and enter the food chain.

Sign of the times

In the U.S., some (human) travelers may soon also require passports even if they don’t leave the country. The 2005 Real ID Act requires that state ID must be compliant with increased security requirements if the holder is to be allowed to board domestic flights. While most states have complied, some have needed an extension. California and Massachusetts, for example, have only until January 10, 2019 to issue the new IDs, otherwise residents will need to show a passport to board a domestic flight.

Town crossing

Fortunately, the number of Americans owning passports has greatly increased in recent years, a phenomenon often attributed to the 2007 law change regarding visiting Mexico and Canada—the previously porous U.S./Canada border is now so restricted that you’ll need a passport just to cross the street in one town—as well as a trend toward investing in experiences over material objects. An indication, perhaps, that this small document is set to become an ever-more important part of our daily lives.